The invention arose during continuing development efforts in improving accumulators or pressure vessels such as shown in U.S. Pat. No. 4,474,215 and allowed U.S. application Ser. No. 07/399,596, filed Aug. 25, 1989, incorporated herein by reference. The invention more particularly relates to improvements in the manner of collapse of the bladder or diaphragm.
An accumulator accumulates a fluid for later usage. For example, in residences having a well, the water pump pumps water into the accumulator which holds the water for later supply to a faucet or the like, without requiring the pump to be turned back on. The accumulator typically comprises a cylindrical vessel having top and bottom ends and a cylindrical sidewall extending axially therebetween. A resilient flexible bladder is disposed within the vessel and has a peripheral edge stationarily secured to the cylindrical sidewall. The bladder separates the vessel into variable volume upper and lower chambers. The bladder is flexibly and deformably movable upwardly and downwardly to increase and decrease the volumes of the upper and lower chambers. For example, when water is pumped into the lower chamber, the bladder moves upwardly and compresses the air in the upper chamber. The pressurized air in the upper chamber is thus available to push the bladder downwardly at a later time when the faucet is turned on.
The present invention arose out of efforts to extend bladder life in applications where the bladder is subject to severe deformation causing cusps which in turn cause high bladder failure rates. In the prior art, problems of buckling or canting of the bladder occurring during collapsing movement have generally been attributed to disorganized movement. Such prior art attempts to prevent disorderly collapse or uncontrolled movement during expulsion, and instead attempts to control such movement, to provide orderly collapse. In contrast, the present invention intentionally permits disorderly collapse during expulsion and permits free and random flexing and deformation of the bladder along randomly oriented and varying planes.
In the present invention, it has been found that the cusp problem is solved by providing a single relatively rigid ring stationarily secured to the bladder and defining a circle on the bladder, wherein during the flexing and deforming movement of the bladder, the circle remains substantially uniplanar with itself but moves with the bladder along variable deformation planes of random orientation. The bladder freely and randomly flexes and deforms such that the circle is randomly oriented along random and varying planes during movement of the bladder during a cycle, and such that the random movement of the plane of the circle randomly varies from cycle to cycle.